c     ****************************************************************
c     *                                                              *
c     *                      subroutine equiv_strain                 *
c     *                                                              *
c     *                       written by : kck                       *
c     *                                                              *
c     *                   last modified : 10/04/94                   *
c     *                                   06/02/95 kck               *        
c     *                                                              *
c     *     this subroutine computes mises yield function value      *
c     *     at the nodes/elem after the primary values have          *
c     *     been averaged                                            * 
c     *                                                              *
c     ****************************************************************
c
      subroutine equiv_strain ( results, maxnum, num )
      implicit integer (a-z)
#dbl      double precision
#sgl      real
     &     results(maxnum,*),  root23, onep5
      data root23, onep5 / 0.471404, 1.5 /
c
      do i = 1, num
        results(i,7) = root23 * sqrt( 
     &     ( results(i,1) - results(i,2) ) ** 2 +
     &     ( results(i,2) - results(i,3) ) ** 2 +
     &     ( results(i,1) - results(i,3) ) ** 2 +
     &   onep5 * ( results(i,4)**2 + results(i,5)**2+
     &         results(i,6)**2 ) )
      end do
c
      return 
      end
